Tabanidae of the East Coast as an economic problem

The author reviews the occurrence and importance of tabanids as pests of man and animals in many areas of the coastal states of the eastern USA. The tabanids are of special importance near salt marshes. The main species, Tabanus nigrovittatus Macq. and Chrysops atlanticus Pechuman move from the marshes to nearby beaches, camping grounds, golf courses and other recreational areas and on to boats in the bays and estuaries. Chrysops congregate in dense vegetation and attack when man or animals move into such places. Both Tabanus and Chrysops are a severe problem to agricultural workers. Livestock are readily attacked by tabanids and the flies have an effect on thriftiness, weight gains and milk production; they may also transmit the causal agents of disease. The biology and habits of both salt-marsh and upland species are poorly known; it is thought that T. nigrovittatus may be a species complex. Some insecticides have given control of either Tabanus or Chrysops, but not both, and some control of Tabanus has been afforded by traps and vegetative barriers; in general, control is inadequate.